Electric vehicle drive units

ABSTRACT

A dual drive unit may include two motors, two power transfer mechanisms, and two output shafts. The output shafts are co-linear. The dual drive unit may include two single drive units, which may be similar to each other, coupled together at a joint, which may optionally include a clutch. A drive unit may be modular, and various components may be combined to provide power to an output shaft. For example, a drive unit may include a differential at a first interface, which may be removable, and two drive units may be coupled together at the first interface. A drive unit may have a Z configuration, wherein a motor on a first side of a vehicle powers a wheel on an opposite side of the vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/599,683 filed Dec. 15, 2017 and U.S. ProvisionalPatent Application No. 62/612,231 filed Dec. 29, 2017, the disclosuresof which are hereby incorporated by reference herein in theirentireties.

INTRODUCTION

Conventional drive units that use two electric motors and two axleoutputs typically align the two motors on the same rotational axis. Therotor shafts of the two motors may, for example, each enter a respectivegearbox that is positioned between the two motors. This results in astack-up of components that makes the drive unit wide, and thereforedifficult to package in certain applications. This can limit, forexample, the length of the motors that can be used, which in turn limitsthe amount of torque and power that the motors can provide. Accordingly,it would be advantageous to provide a drive unit configuration that isshaped more conveniently for packaging. It would also be advantageous toprovide a drive unit that enables a wider range of motors andaccompanying components to be used.

Conventional drive units and associated gearboxes are typically designedfor specific applications. For example, gearboxes are typically designedto be used in a single motor drive unit or a dual motor drive unit, butnot both. As another example, a gearbox is typically designed to be usedin a particular orientation and for driving a set number of wheels.Accordingly, it would be advantageous to provide modular drive unitcomponents that can be used for more than one application. It would alsobe advantageous to provide modular drive unit components that can beused in more than one orientation. It would also be advantageous toprovide modular drive units which may be independent or coupled to adaptto changing driving conditions.

SUMMARY

In some embodiments, the present disclosure is directed to a drivesystem. The drive system includes a first output shaft configured torotate about a drive axis and a second output shaft configured to rotateabout the drive axis. The first output shaft and the second output shaftare orientated away from each other. For example, the output shafts arearranged co-linearly on the axis. The drive system includes a firstmotor having a first motor shaft that rotates about a first motor axis.The first motor axis is parallel to the drive axis. The drive systemincludes a second motor having a second motor shaft that rotates about asecond motor axis. The first motor axis is parallel to and spaced apartfrom the second motor axis. The drive system includes a first powertransfer mechanism configured to couple rotation of the first motorshaft to rotation of the first output shaft. The drive system includes asecond power transfer mechanism configured to couple rotation of thesecond motor shaft to rotation of the second output shaft.

In some embodiments, the first power transfer mechanism and the secondpower transfer mechanism each include a gear train.

In some embodiments, the gear train of the first power transfermechanism and the second power transfer mechanism each include a firstgear, at least one second gear, and a third gear. The first gear iscoupled to a corresponding motor shaft. The at least one second gear iscoupled to an intermediate shaft. The third gear is coupled to acorresponding output shaft. The first gear mechanically interfaces withthe at least one second gear and the at least one second gearmechanically interfaces with the third gear.

In some embodiments, the at least one second gear includes two gearscoupled to the intermediate shaft. The two gears include a first largergear and a second smaller gear. The first larger gear mechanicallyinterfaces with the first gear, and the second smaller gear mechanicallyinterfaces with third gear. The first power transfer mechanism and thesecond power transfer mechanism each provide a gear reduction between amotor shaft and corresponding output shaft.

In some embodiments, the intermediate shaft is offset from a lineconsidered to extend from the motor shaft to the output shaft.

In some embodiments, the first power transfer mechanism includes a firsthousing extending between the first motor shaft and the first outputshaft. The first housing includes an indentation to accommodate thesecond motor. The second power transfer mechanism includes a secondhousing extending between the second motor shaft and the second outputshaft. The second housing includes an indentation to accommodate thefirst motor.

In some embodiments, when the drive system is viewed perpendicular tothe drive axis, the first power transfer mechanism at least partiallyoverlaps with the second motor and the second power transfer mechanismat least partially overlaps with the first motor.

In some embodiments, the first power transfer mechanism includes a firstend proximate to the first motor axis and a second end proximate to thefirst output shaft. The second end of the first power transfer mechanismis located a first distance away from the first motor axis, which isgreater than a distance from the first motor axis to an outer sidesurface of the first motor. The second power transfer mechanism includesa first end proximate to the second motor axis and a second endproximate to the second output shaft. The second end of the second powertransfer mechanism is located a second distance away from the secondmotor axis, which is greater than a distance from the second motor axisto an outer side surface of the second motor. The second end of thefirst power transfer mechanism is adjacent to the second end of thesecond power transfer mechanism.

In some embodiments, the second end of the first power transfermechanism is mechanically connected to the second end of the secondpower transfer mechanism.

In some embodiments, the first power transfer mechanism and the secondpower transfer mechanism each include a chain drive or a belt drive.

In some embodiments, the first motor shaft and the second motor shaft atleast partially overlap when viewed in a direction perpendicular to thefirst motor axis.

In some embodiments, the first motor includes a first motor housing andthe second motor includes a second motor housing. The first motorhousing and the second motor housing partially overlaps when viewed in adirection perpendicular to the first motor axis.

In some embodiments, the first motor shaft extends from the first motorin a first direction and wherein the first output shaft extends from thefirst power transfer mechanism in the first direction.

In some embodiments, the second motor shaft extends from the secondmotor in a second direction, wherein the second output shaft extendsfrom the second power transfer mechanism in the second direction, andwherein the first direction and second direction are oppositedirections.

In some embodiments, when the drive system is viewed parallel to thedrive axis, first motor axis, and second motor axis and when a firstline is considered to extend from the drive axis to the first motor axisand when a second line is considered to extend from the drive axis tothe second motor axis, an angle between the first line and the secondline is less than 90 degrees.

In some embodiments, the drive system includes a first invertorconfigured to control the operation one of the first motor and thesecond motor, wherein the first inverter is aligned with first motoraxis and mechanically coupled to the first power transfer mechanism. Insome embodiments, the drive system includes a second invertor configuredto control the operation the other of the first motor and the secondmotor, wherein the second inverter is aligned with second motor axis andmechanically coupled to the second power transfer mechanism.

In some embodiments, the drive system includes a clutch assembly coupledto the first output shaft and the second output shaft, wherein theclutch assembly, when engaged, is configured to lock the first outputshaft and the second output shaft together.

In some embodiments, the drive system includes a first half shaft,wherein a first end of the first half shaft is coupled to the firstoutput shaft. The drive system includes a first wheel, wherein a secondend of the first half shaft is coupled to the first wheel. In someembodiments, the drive system includes a second half shaft, wherein afirst end of the second half shaft is coupled to the second outputshaft, and a second wheel, wherein a second end of the second half shaftis coupled to the second wheel.

In some embodiments, the present disclosure is directed to a drivesystem having a clutch assembly. The drive system includes a first motorhaving a first motor shaft configured to rotate. The drive systemincludes a first output shaft configured to rotate about a drive axis.The drive system includes a first power transfer mechanism configured tocouple rotation of the first motor shaft to rotation of the first outputshaft and reduce a rotation rate of the first output shaft relative to arotation rate of the first motor shaft. The drive system includes asecond motor having a second motor shaft configured to rotate. The drivesystem includes a second output shaft configured to rotate about thedrive axis. The drive system includes a second power transfer mechanismconfigured to couple rotation of the second motor shaft to rotation ofthe second output shaft and reduce a rotation rate of the second outputshaft relative to a rotation rate of the second motor shaft. The clutchassembly is coupled to the first output shaft and the second outputshaft, wherein the clutch assembly, when engaged, is configured totransfer torque between the first output shaft and the second outputshaft.

In some embodiments, the clutch assembly includes one of a slip clutchand a non-slip clutch.

In some embodiments, the first motor shaft is configured to rotate abouta first motor axis, the second motor shaft is configured to rotate abouta second motor axis, and the first motor axis and the second motor axisare parallel to each other and offset with respect to each other.

In some embodiments, the first power transfer mechanism and the secondpower transfer mechanism each include a gear train.

In some embodiments, the gear train of the first power transfermechanism and the second power transfer mechanism each include a firstgear, at least one second gear, and a third gear. The first gear iscoupled to a corresponding motor shaft. The at least one second gear iscoupled to an intermediate shaft. The third gear is coupled to acorresponding output shaft, wherein the first gear mechanicallyinterfaces with the at least one second gear and wherein the at leastone second gear mechanically interfaces with the third gear.

In some embodiments, the at least one second gear includes a firstlarger gear and a second smaller gear coupled to the intermediate shaft.The first larger gear mechanically interfaces with the first gear andthe second smaller gear mechanically interfaces with the third gear. Thefirst power transfer mechanism and the second power transfer mechanismeach provide a gear reduction between the corresponding motor shaft andthe corresponding output shaft.

In some embodiments, each intermediate shaft is offset from a lineconsidered to extend from the corresponding motor shaft to thecorresponding output shaft.

In some embodiments, the first power transfer mechanism includes a firsthousing extending between the first motor shaft and the first outputshaft. The first housing includes an indentation to accommodate thesecond motor. The second power transfer mechanism includes a secondhousing extending between the second motor shaft and the second outputshaft. The second housing includes an indentation to accommodate thefirst motor.

In some embodiments, when the drive system is viewed perpendicular tothe drive axis, the first power transfer mechanism at least partiallyoverlaps with the second motor and the second power transfer mechanismat least partially overlaps with the first motor.

In some embodiments, the first power transfer mechanism includes a firstend proximate to the first motor shaft and a second end proximate to thefirst output shaft. The second end of the first power transfer mechanismis located a first distance away from the first motor shaft, which isgreater than a distance from the first motor shaft to an outer sidesurface of the first motor. The second power transfer mechanism includesa first end proximate to the second motor shaft and a second endproximate to the second output shaft. The second end of the second powertransfer mechanism is located a second distance away from the secondmotor shaft, which is greater than a distance from the second motorshaft to an outer side surface of the second motor. The second end ofthe first power transfer mechanism is adjacent to the second end of thesecond power transfer mechanism.

In some embodiments, the first power transfer mechanism and the secondpower transfer mechanism each include a chain drive or a belt drive.

In some embodiments, the first motor shaft extends from the first motorin a first direction and the first output shaft extends from the firstpower transfer mechanism in the first direction.

In some embodiments, the second motor shaft extends from the secondmotor in a second direction, the second output shaft extends from thesecond power transfer mechanism in the second direction, and the firstdirection and second direction are opposite directions.

In some embodiments, when the drive system is viewed parallel to thedrive axis, first motor shaft, and second motor shaft and when a firstline is considered to extend from the drive axis to the first motorshaft and when a second line is considered to extend from the drive axisto the second motor shaft, an angle between the first line and thesecond line is less than 90 degrees.

In some embodiments, a drive system includes a first inverter configuredto control the operation of one of the first motor and the second motor,wherein the first inverter is aligned with the first motor shaft andmechanically coupled to the first power transfer mechanism. In someembodiments, a drive system includes a second inverter configured tocontrol the operation of the other of the first motor and the secondmotor, wherein the second inverter is aligned with the second motorshaft and mechanically coupled to the second power transfer mechanism.

In some embodiments, the first power transfer mechanism includes a firsthousing, the second power transfer mechanism includes a second housing,and the clutch assembly includes a clutch housing. The clutch housing isconfigured to rigidly couple to both the first housing and the secondhousing.

In some embodiments, a drive system includes a first half shaft, whereina first end of the first half shaft is coupled to the first outputshaft. The drive system includes a first wheel, wherein a second end ofthe first half shaft is coupled to the first wheel. The drive systemincludes a second half shaft, wherein a first end of the second halfshaft is coupled to the second output shaft. The drive system includes asecond wheel, wherein a second end of the second half shaft is coupledto the second wheel.

In some embodiments, a drive system includes processing equipmentconfigured to activate and deactivate the clutch assembly.

In some embodiments, a drive system includes at least one sensorconfigured to sense wheel slippage. The processing equipment is furtherconfigured to receive a signal from the at least one sensor, detect thatwheel slippage is occurring based on the signal, and activate the clutchassembly in response to detecting that wheel slippage is occurring.

In some embodiments, a drive system includes an accelerator pedalconfigured to indicate a desired speed. The processing equipment isfurther configured to receive a signal from the accelerator pedal,determine a speed parameter based on the signal, and activate the clutchassembly if the speed parameter is above a threshold.

In some embodiments, the processing equipment is configured to identifya drive mode, and activate and deactivate the clutch assembly based onthe identified drive mode.

In some embodiments, the processing equipment is configured to determineat least one road condition, and activate or deactivate the clutchassembly based at least in part on the at least one road condition.

In some embodiments, the present disclosure is directed to a method formanaging a drive system. The method includes determining at least oneparameter, determining whether to change a clutch setting based on theat least one parameter, and activating or deactivating the clutchassembly when it is determined to change the setting.

In some embodiments, the present disclosure is directed to a modulardrive system. The modular drive system includes a gearbox housing. Thegearbox housing includes a motor mount configured for mounting of anelectric motor. The gearbox housing includes a first space within thegearbox housing capable of receiving an input gear capable of beingcoupled to the electric motor. The gearbox housing includes a secondspace within the gearbox housing capable of receiving an output gear.The gearbox housing includes at least one intermediate gear mountedwithin the first gearbox housing. The at least one intermediate gear isconfigured to mechanically interface with the input gear andmechanically interface with the output gear. The gearbox housingincludes a first opening in a first side of the gearbox housing adjacentto the second space. The gearbox housing includes a second opening in asecond side of the gearbox housing adjacent to the second space. Thefirst side and the second side are opposite sides of the gearboxhousing. The second opening is configured to enable an output shaft topass through to drive a first wheel. The first opening includes a mountconfigured for mounting of a differential housing and a cover plate.When the differential housing is mounted to the mount, the modular drivesystem is capable of driving two wheels. When the cover plate is mountedto the mount, the modular drive system is capable of driving the firstwheel.

In some embodiments, the at least one intermediate gear includes acompound gear having a larger gear and a smaller gear. The larger gearis configured to mechanically interface with the input gear and thesmaller gear is configured to mechanically interface with the outputgear.

In some embodiments, the gearbox housing is a first gearbox housing andthe output shaft is a first output shaft having a first rotational axis.At least one of the cover plate and the gearbox housing is configuredfor attachment to a second gearbox housing. The second gearbox housingincludes a second output shaft having a second rotational axis. When thesecond gearbox housing is attached to the first gearbox housing, thefirst rotational axis and the second rotational axis are aligned.

In some embodiments, the electric motor is a first electric motor andthe second gearbox housing further includes a motor mount configured formounting of a second electric motor.

In some embodiments, the first gearbox housing and the second gearboxhousing each provide a gear reduction between a corresponding motorshaft and corresponding output shaft.

In some embodiments, the gearbox housing further includes anintermediate shaft. The at least one intermediate gear is mounted to theintermediate shaft and the intermediate shaft is offset from a lineconsidered to extend from a center of the input gear to a center of theoutput shaft.

In some embodiments, the first gearbox housing includes an indentationto accommodate the second motor and the second gearbox housing includesan indentation to accommodate the first motor.

In some embodiments, the first output shaft rotates about a first driveaxis. When the modular drive system is viewed perpendicular to the driveaxis, the first gearbox housing at least partially overlaps with thesecond motor and the second gearbox housing at least partially overlapswith the first motor.

In some embodiments, the first gearbox housing includes a first endproximate to a first motor shaft of the first motor and a second endproximate to the first output shaft. The second end of the first gearboxhousing is located a first distance away from the first motor shaft,which is greater than a distance from the first motor shaft to an outerside surface of the first motor. The second gearbox housing includes afirst end proximate to a second motor shaft of the second motor and asecond end proximate to the second output shaft. The second end of thesecond gearbox housing is located a second distance away from the secondmotor shaft, which is greater than a distance from the second motorshaft to an outer side surface of the second motor. The second end ofthe first gearbox housing is adjacent to the second end of the secondgearbox housing.

In some embodiments, the second end of the first gearbox housing ismechanically connected to the second end of the second gearbox housing.

In some embodiments, a motor shaft of the electric motor extends fromthe electric motor in a first direction and wherein the output shaftextends from the gearbox housing in the first direction.

In some embodiments, the modular drive system includes an inverterconfigured to control the operation of the electric motor, wherein theinverter is aligned with the motor shaft and mechanically coupled to thegearbox housing.

In some embodiments, the gearbox housing is a first gearbox housing. Themount is further configured for mounting of a clutch assembly coupled toa second gearbox housing. The output shaft is a first output shafthaving a first rotational axis. The second gearbox housing includes asecond output shaft having a second rotational axis. When the clutchassembly coupled to the second gearbox housing is mounted to the mount,the first rotational axis and the second rotational axis are aligned.

In some embodiments, the present disclosure is directed to a method ofconfiguring the modular drive system. The method includes determining adesired drive configuration, mounting the differential housing to themount when the desired configuration is a single drive configuration,and mounting the cover plate to the mount when the desired configurationis a dual drive configuration.

In some embodiments, the present disclosure is directed to a gearboxcapable of being used in two different orientations. The gearboxincludes a gearbox housing. The gearbox housing includes a motor mountconfigured for mounting of an electric motor. The gearbox housingincludes a first space within the gearbox housing capable of receivingan input helical gear capable of being coupled to the electric motor.The gearbox housing includes a second space within the gearbox housingcapable of receiving an output helical gear capable of being coupled toan output shaft. The gearbox housing includes at least one intermediatehelical gear mounted within the gearbox housing. The at least oneintermediate helical gear is configured to mechanically interface withthe input gear and mechanically interface with the output gear. Each ofthe at least one intermediate helical gear is capable of being mountedin a first gear orientation and a second gear orientation. The secondgear orientation is rotated 180 degrees, from the first gearorientation, about an axis perpendicular to an axis of rotation of therespective intermediate helical gear. Each of the at least oneintermediate helical gear is mounted in the first gear orientation whenthe gearbox housing is intended to be used in a first gearboxorientation. Each of the least one intermediate helical gear is mountedin the second gear orientation when the gearbox housing is intended tobe used in a second gearbox orientation. The second gearbox orientationis rotated 180 degrees, from the first gearbox orientation, about anaxis perpendicular to the drive axis.

In some embodiments, the at least one intermediate helical gear includesa compound gear having a larger helical gear and a smaller helical gear.The larger gear is configured to mechanically interface with the inputgear and the smaller gear is configured to mechanically interface withthe output gear.

In some embodiments, the at least one intermediate helical gear providesa gear reduction between a motor shaft of the electric motor and theoutput gear.

In some embodiments, the at least one intermediate helical gear ismounted to an intermediate shaft, and wherein the intermediate shaft isoffset from a line considered to extend from the motor shaft to theoutput gear.

In some embodiments, the present disclosure is directed to a method forconfiguring a gearbox. The method includes determining an intendedgearbox orientation of the gearbox housing and mounting each of the atleast one helical gear in the first gear orientation or the second gearorientation based on the intended gearbox orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments. These drawings areprovided to facilitate an understanding of the concepts disclosed hereinand shall not be considered limiting of the breadth, scope, orapplicability of these concepts. It should be noted that for clarity andease of illustration these drawings are not necessarily made to scale.

FIG. 1 shows a perspective view of an illustrative dual drive unit, inaccordance with some embodiments of the present disclosure;

FIG. 2 shows an end view of the illustrative dual drive unit of FIG. 1 ,in accordance with some embodiments of the present disclosure;

FIG. 3 shows a side view of the illustrative dual drive unit of FIG. 1 ,in accordance with some embodiments of the present disclosure;

FIG. 4 shows an illustrative arrangement of gears within the gearboxesof FIGS. 1-3 , in accordance with some embodiments of the presentdisclosure;

FIG. 5 shows an end view of an illustrative “C” type dual drive unit, inaccordance with some embodiments of the present disclosure;

FIG. 6 shows an end view of an illustrative “Z” type dual drive unit, inaccordance with some embodiments of the present disclosure;

FIG. 7 shows illustrative panels of how two halves of a dual drive unitmay be coupled together, in accordance with the present disclosure;

FIG. 8 shows illustrative panels of how two halves of a dual drive unitmay be coupled together to replace a differential, in accordance withthe present disclosure;

FIG. 9 shows illustrative panels of how a clutch assembly may beinstalled to couple two drive units, in accordance with some embodimentsof the present disclosure;

FIG. 10 shows a block diagram of an illustrative electric vehicle havinga control system for controlling one or more drive units, in accordancewith some embodiments of the present disclosure; and

FIG. 11 shows a perspective view of an illustrative dual drive unithaving a single gear housing, in accordance with some embodiments of thepresent disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to improvements in motor drive unitarchitectures. In some embodiments, the motor drive unit architecturealigns two motors on different axes. In some embodiments, thisarchitecture enables longer motors (e.g., for providing more torque andpower) to be packaged and/or decreases the width of the drive unit. Insome embodiments, the present disclosure is directed to drive unitshaving modularity, allowing a plurality of configurations to berealized. In some embodiments, this architecture also enables severaldifferent arrangements for packaging power electronics. Accordingly, insome embodiments, the dual motor drive unit is able to accommodate awide variety of available motors and inverters.

In some circumstances, dual drive units provide various advantages,including the ability to provide torque vectoring. The dual drive unitsof the present disclosure may provide one or more advantages overconventional dual drive units. In some embodiments, the dual drive unitsof the present disclosure may be configured to fit into vehicles thatare otherwise too small to fit the necessary hardware. This enablestorque vectoring drive units to be appropriately packaged in smallerpassenger vehicles. In some embodiments, the dual drive units of thepresent disclosure enable the use of relatively larger motors to fit inhigh performance applications that already employ torque vectoring driveunits. This results in even more power in high output torque vectoringcars. In some embodiments, the dual drive units of the presentdisclosure enable the use of longer half shafts, which means moresuspension travel is possible without compromising vehicle speed.Therefore, off-road applications or modes that require more suspensiontravel overall can be used at much higher speeds than with conventionaldual motor drive units.

FIG. 1 shows a perspective view of illustrative dual drive unit 100, inaccordance with some embodiments of the present disclosure. FIG. 2 showsan end view of illustrative dual drive unit 100 of FIG. 1 , inaccordance with some embodiments of the present disclosure. FIG. 3 showsa side view of illustrative dual drive unit 100 of FIG. 1 , inaccordance with some embodiments of the present disclosure. Dual driveunit 100 may be considered to have opposite halves: motor 110 andgearbox 112 form one half, and motor 120 and gearbox 122 form a secondhalf. As illustrated, each half includes a motor (e.g., motor 110 or120), a gearbox (e.g., gearbox 112 or 122), and an output (e.g., outputshaft 114 or 124). In some embodiments, motors 110 and 120 each includea motor shaft that is configured to rotate about a respective motor axis(e.g., using roller bearings).

As illustrated in FIGS. 1-3 , the motor axes are parallel to each other,but spaced apart (e.g., parallel but not co-linear). This configurationenables the drive shafts, which extend from the motors to overlap eachother (axially, shown in FIG. 2 ) when viewing the motors perpendicularto the motor axes. Further, this configuration enables the gearbox foreach motor to be positioned on the opposite side of the other gearboxand power the wheel on the opposite side of the car as the correspondingmotor. For example, referencing FIG. 2 , motor 110 on the right isconfigured to provide power to the left wheel. As illustrated in FIG. 2, the gearbox for each motor extends past the gearbox for the opposingmotor and then aligns at the far end by the output shaft (e.g., theoutput shafts have axes that are co-linear). In some embodiments, theends of gearboxes 112 and 122 that are proximate to output shafts 114and 124 are mechanically coupled together. For example, gearboxes 112and 122 may be bolted together along the outside seam where they meet(e.g., which may include a flange having locating pins). As illustratedin FIG. 3 , gearbox 122 includes an indentation 125, with correspondingprotrusion 126, to accommodate motor 110. This enables tight, efficientpacking of motors 110 and 120, and corresponding gearboxes 112 and 122.In some embodiments, to accommodate the indentation (e.g., indentation115 or 125) and/or protrusion (e.g., protrusion 116 or 126) in the gearbox, the gearset may include an intermediate gear that is configured torotate about an axis that is offset from a line connecting the motorshaft and the output shaft. For example, to accommodate the offset, theopposite side of the gearbox may then need a protrusion, as illustratedby protrusions 116 and 126. In some embodiments, a gearbox may beshaped, or otherwise have features included, based on constraints suchas, for example, oil circulation, avoidance of interfering components,achieving a desired rigidity, ease of mounting, ease of installation,any other suitable constraint, or any combination thereof. For example,as illustrated in FIG. 3 , gearbox 122 includes an intermediate gearoffset from the output shaft and motor shaft (e.g., giving gearbox 122 aslight v-shaped profile 190). In some embodiments, the angle of theprofile 190 may include any suitable angle (e.g., less than 90 degrees,or greater than 90 degrees).

In some embodiments, motor 110, motor 120, or both, may include coolingpassages configured to direct coolant flow. Because the single driveunits are coupled together, the cooling passages of the two halves mayinterface. For example, each motor may include serpentine channelshaving an inlet and outlet port, and each of gearboxes 112 and 122 mayinterface to the inlet and outlet, and also include passages connectingthe inlets and outlets of the two motors together (e.g., in series orparallel). In some embodiments, gearboxes 112 and 122 include coolingpassages configured for cooling of oil, cooling of bearings, cooling ofthe housing structure, cooling of any other suitable component, or anycombination thereof.

FIG. 4 shows an illustrative arrangement 400 of gears within gearboxes,in accordance with some embodiments of the present disclosure. Gearboxhousings are not illustrated in FIG. 4 for clarity. As illustrated, eachgearset (e.g., gears 411, 415, 416, and 414 are one gearset, and gears421, 425, 426, and 424 are another gearset) includes a double reductiongear. Each motor (e.g., motor 410 and motor 420), includes a motor shafthaving a first gear. For example, first gear 411 is affixed to the shaftof motor 410, and first gear 421 is affixed to the shaft of motor 420.Each first gear pairs with a larger of two intermediate gears thatrotate about an intermediate axis. For example, first gear 411 engageswith intermediate gear 415 affixed to an intermediate shaft.Intermediate gear 416, coupled to the same intermediate shaft asintermediate gear 415 engages with respective output gear 414 (e.g.,coupled to a respective output shaft 418). Further, first gear 421engages with intermediate gear 425 affixed to an intermediate shaft.Intermediate gear 426, coupled to the same intermediate shaft asintermediate gear 425 engages with respective output gear 424 (e.g.,coupled to a respective output shaft 428, aligned with output shaft418). It will be understood that, as illustrated in FIG. 4 , outputgears 414 and 424 are aligned, with output gear 424 being positionedbehind output gear 414, and only output shaft 418 visible. As describedherein, the intermediate shafts may be offset (e.g., not aligned along aline) from the respective motor shaft and drive shaft. It will beunderstood that any suitable number of gears may be used with anysuitable amount of reduction between a motor and corresponding outputshaft. In some embodiments, the gearbox may include two or more gears ina gear train. The gear train may include an ordinary gear train or acompound ordinary gear train. For example, a compound gear train mayinclude two gears configured to rotate about a single axis. Gears mayinclude any suitable gear types such as, for example, spur gears,parallel helical gears, any other suitable gear type, or any suitablecombination thereof. It will be understood that while the illustrativedrive units of the present disclosure are illustrated as includinggearboxes and gears, any suitable power transfer mechanisms may be usedto transfer power from a motor to an output, in accordance with thepresent disclosure. For example, chain drives, belt drives may be used.In a further example, a belt tensioner, cog, sprocket, any othersuitable hardware, or combination thereof, may be included to transferpower, maintain engagement, or both.

FIG. 5 shows an end view of illustrative “C” type dual drive unit 500,in accordance with some embodiments of the present disclosure. Dualdrive unit 500 may be used as a torque vectoring drive unit (e.g., toapply a different torque to each wheel). As illustrated, the motors arealigned along the same rotational axis (e.g., are co-linear) and thecorresponding gear boxes are positioned between the two motors (e.g.,motor+gearbox 510, and motor+gearbox 520). The output shaft for eachmotor is oriented in the opposite direction as the corresponding motorshaft. For example, the motor of motor+gearbox 520 is configured todrive the right wheel (e.g., via output shaft 524) while the motor ofmotor+gearbox 510 is configured to drive the left wheel (e.g., viaoutput shaft 514). This type of drive unit is referred to herein as a“C” type drive unit. The width 550 of dual drive unit 500 includes thefull width of motor+gearbox 510 and motor+gearbox 520.

FIG. 6 shows an end view of illustrative “Z” type dual drive unit 600having a “Z” configuration, in accordance with some embodiments of thepresent disclosure. Dual drive unit 600 includes two drive units ofsimilar size to that illustrated in FIG. 5 . However, the “Z”configuration of dual drive unit 600 has an associated width 650 lessthan that of width 550 of FIG. 5 . For example, the motor ofmotor+gearbox 620 is configured to drive the left wheel (e.g., viaoutput shaft 624) while the motor of motor+gearbox 610 is configured todrive the right wheel (e.g., via output shaft 614). By aligning themotors along different parallel axes (e.g., not co-linear), the width650 of the dual drive unit is substantially reduced as compared to dualdrive unit 500 of FIG. 5 . In some embodiments, for example, the reducedwidth 650 may be less than the width 550 by the combined widths of thegearboxes. For example, centerline 660 is shown aligned with the middleof dual drive unit 600, and the gearbox for each motor is on theopposite side of centerline than the corresponding motor. In thisarrangement, the gearbox for one motor overlaps the other motor whenviewed in a direction perpendicular to the axes of the motors. In someembodiments, the first and second motors can partially overlap acrosscenterline 660 as well (e.g., by using a compound gear train). In someembodiments, a reduced width (e.g., width 650 as compared to width 550)and “v-shaped” configuration may allow for a more powerful motor (e.g.,a larger motor), or more robust gearbox (e.g., a larger gearbox) to beincluded.

FIG. 7 shows illustrative panels of how two halves of a dual drive unitmay be coupled together, in accordance with the present disclosure.Drive unit 710 and drive unit 720 may be coupled together to form dualdrive unit 750. For example, region 713 of gearbox 712 may be coupled toa corresponding region (not shown) of gearbox 722 to form dual driveunit 750. To illustrate, drive units 710 and 720 are connected to eachother such that the output shafts are aligned along a common axis (e.g.,a drive axis) as shown by dual drive unit 750. As illustrated in FIG. 7, drive unit 710 includes power electronics 713 (e.g., an inverter) anddrive 720 includes power electronics 723 (e.g., an inverter). Forexample, power electronics 713 and 723 may be configured to control theoperation of respective motors 711 and 721. Power electronics 713 and723 are aligned with respective motors 711 and 721, and are positionedon the opposite side of respective gearboxes 712 and 722 from respectivemotors 711 and 721. It will be understood that a “drive axis” refers tothe axis of rotation of output gears, output shafts, or both, and mayalso nominally refer to the corresponding axis of rotation of halfshafts and wheels as well (even though suspension travel may render thewheel axis and half shaft axis different from the output gear).

FIG. 8 shows illustrative panels of how two halves of a dual drive unitmay be coupled together to replace a differential, in accordance withthe present disclosure. Drive unit 810 includes motor 811, powerelectronics 813, a power transfer mechanism 812 (e.g., a gearboxhousing), and differential 817. The first motor may be, for example, anelectric motor (e.g., an AC induction motor), of any suitable phasecount (e.g., a 3-phase motor), configured to drive two wheels (e.g.,“Wheel 1” and “Wheel 2”) on a drive axis. Differential 817 is configuredto provide power to two output shafts (e.g., two rear wheels, or twofront wheels). Power electronics 813 may include an inverter configuredto convert DC power to AC power (e.g., convert voltage and current of aDC bus to 3-phase AC voltage and current for a 3-phase motor 811). Insome embodiments, motor 811 may include a DC motor, and accordingly,power electronics 813 need not be included, or need not include aninverter (e.g., other components such as a DC-DC converter mayoptionally be included). Differential 817 may include any suitabledifferential type such as, for example, an open differential, a limitedslip differential, a locking differential, a spool (mechanicallylocked), an electronically controlled differential, or any othersuitable differential. Differential 817 may be configured to receive asingle input from power transfer mechanism 812 (e.g., from an outputgear of a gearbox housing), and drive two shafts coupled to tworespective wheels on a drive axis. Accordingly, drive unit 810 is anexample of a drive unit having a single motor configured for driving twowheels on a drive axis, via power transfer mechanism 812 (e.g., agearbox housing) and differential 817.

In some embodiments, drive unit 810 may be converted to drive unit 820,wherein, for example, differential 817 is removed. In some embodiments,after removal of differential 817, drive unit 820 may be coupled todrive unit 830 to form dual drive unit 850. The conversion from driveunit 810 to dual drive unit 850 may be illustratively performed byremoving differential 817 from power transfer mechanism 812, installinga cover plate onto power transfer mechanism 812 where differential 817used to be, and then coupling drive unit 820 and drive unit 830 together(e.g., wherein drive unit 830 may, but need not, include a cover plate).In some embodiments, housings of power transfer mechanisms 812 and 832may be bolted together, or otherwise affixed to one another, to providestructural rigidity. Motor 831 and power transfer mechanism 832 may besubstantially similar to respective motor 811 and power transfermechanism 812, but positioned 180° around an axis normal to the driveaxis.

Under most circumstances, wheel 1 and wheel 2 are desired to turn in thesame direction, even if not at the same speed. Accordingly, motor 811and motor 831 may be configured to rotate in the same direction as theoutput gears (e.g., and wheels). Further, for dual drive unit 850, powertransfer mechanism 832 would turn in the opposite orientation as powertransfer mechanism 812. For example, if power transfer mechanisms 812and 832 include gearboxes, the second gear-train (i.e., of powertransfer mechanism 832) would be spinning in the opposite direction thanthe first gear-train (i.e., of power transfer mechanism 812), relativeto the respective gearbox housings. In some circumstances, this may beundesirable in view of gear lash and chatter, and accordingly, it may bedesired to mount each of the gears of the second gearbox rotated 180°about a respective axis normal to the respective axis of rotation (e.g.,remove a gear, flip it around 180°, and reinstall on the same shaft).Accordingly, in some embodiments, for a given set of hardware, a powertransfer mechanism may be configurable for a particular drive direction,which reduces, or eliminates, the need for additional components. Insome embodiments, reconfiguration may require, for example, flippinggears, re-aligning gears, re-lashing gears, performing measurements, orother suitable actions.

In some embodiments, it may be desirable to create dual drive unit 850by using two similar, or identical, single drive units (e.g., driveunits 820 and 830). In addition to the gear rotation direction (e.g.,discussed above), there are several other considerations which mayimpact the extent to which the drive units are identical. The locationof an oil pump (e.g., gear driven from a gear of the corresponding powertransfer mechanism), oil pickup, oil sump, or otherwise location of allor part of the oiling system of a power transfer mechanism may impactthe conversion from single to dual drive unit configurations, andorientations of the power transfer mechanisms therein. For example,referencing FIG. 8 , power transfer mechanisms 812 and 832 may havedifferent drop angles for oil in the bottom of respective gearboxhousings. Accordingly, an oil pickup, for example, may need to be moved,or otherwise adjusted, to accommodate the relative difference inorientation of the power transfer mechanisms. In some embodiments,multiple oil pickups are integrated in the power transfer mechanism andthe appropriate one is used based on the drop angle. For example, theunused oil pickups may be sealed or capped off. It would be desirable tobe able to accommodate drop angles ranging from 0° to 90°. A furtherconsideration may be that a gear driven oil pump for the housings mayspin in opposite directions. For example, in addition to “flipping thegears” of the power transfer mechanism, an oil pump drive gear may alsoneed to be flipped. Another consideration is that the first and secondmotors may rotate in opposite directions, relative to the local motorhousing, when the output shafts are spinning together. For example,referencing FIG. 8 , when viewed from the respective power electronics'ends (e.g., ends of power electronics 813 and 833), if motor 831 isturning clockwise (CW), and Wheel 1 and Wheel 2 are turning in the samedirection, motor 811 is turning counter clockwise (CCW). In someembodiments, motor 831, motor 811, or both, may need to be adjusted fordual drive unit 850. For example, for some 3-phase motors andcontrollers, two phases may need to be swapped to impart the desireddirection to the motor.

Power transfer mechanism 812, which may include a gearbox housing, maybe configured to couple a motor shaft of motor 811 to an output gearcoupled to differential 817. In some embodiments, power transfermechanism 812 may include a motor mount configured for mounting of motor811, as well as a first space to accommodate an input gear (e.g., afirst gear) coupled to motor 811. In some embodiments, power transfermechanism 812 may also include a second space to accommodate an outputgear (e.g., coupled to differential 817 as illustrated by drive unit810). In some embodiments, power transfer mechanism 812 may include atleast one intermediate gearset which interfaces with the input gear andthe output gear, providing a gear reduction from the motor to the output(e.g., the motor shaft rotates faster, with less torque, than the outputshaft, typically). In some embodiments, power transfer mechanism 812 mayinclude a first opening in a first side of the housing adjacent to thesecond space to accommodate differential 817, a cover plate, or both.For example, the first opening may include a mount for mountingdifferential 817 and cover plate 827 (e.g., depending on theconfiguration). A second opening on the opposite side may accommodate anoutput shaft, which may couple the output gear to Wheel 1 (e.g., viacoupling and half shaft). When differential 817 is mounted to powertransfer mechanism 812, drive unit 810 may drive both Wheel 1 and Wheel2. When cover plate 827 is mounted to the mount, thus forming drive unit820, drive unit 820 may drive Wheel 1. Power transfer mechanism 832 mayhave similar attributes, and accordingly is configured to drive Wheel 2when coupled to power transfer mechanism 812, as shown by dual driveunit 850.

In some embodiments, conversion from drive unit 810 to dual drive unit850, or assembling dual drive unit 850 without conversion, may include,for example, mechanical installation steps including mechanicalcomponents. For example, an output gear, an output shaft, and/or one ormore bearings may be replaced or installed, one or more gaskets, seals(e.g., shaft seals) may be installed, one or more cover plates may beinstalled, one or more spacers may be installed, any other suitablecomponents may be installed, removed, or replaced, or any combinationthereof. For example, in some embodiments, one or more components may beswapped, replaced, or otherwise changed to accommodate the conversion.

In some embodiments, a configuration similar to drive unit 810 may bedesired, but with a different differential (e.g., different fromdifferential 817). In some embodiments, the present disclosure isdirected to a modular drive system that allows, for example, differentdifferentials, or other components, to be installed. For example, insome circumstances an open differential may be included, while in othercircumstances, a limited slip differential or locking differential maybe included. Accordingly, a single drive unit may be converted from onedifferential type to another, or may be built up using any suitabledesired differential (e.g., not converted but built as desired fromconstituent components).

The ability to use a single drive unit, and components thereof, toconstruct a dual drive unit based on powertrain requirements may reduce,or eliminate, the need to scale a powertrain design (e.g., re-engineer,re-tool, re-manufacture components). In some embodiments, for example, asingle drive unit may be sized to accommodate the powertrainrequirements of a small, or low performance, vehicle. Accordingly,another single drive unit may be installed to create a dual drive unitto accommodate increased powertrain demands without having to scalepowertrain components (e.g., rather than making components bigger, addmore of the same components).

In some circumstances, modularity may reduce the number of unique partsamong various drive configurations, and also reduceengineering-design-development (ED&D) efforts, lead time, and cost. Forexample, while a single drive unit having higher power/torque output canbe designed and manufactured using new unique components, a dual driveunit may be used instead to achieve the same power/torque outputcapability, but with an increase in the number of total parts in thebuild as compared to the single drive unit (e.g., roughly double thenumber of parts). In addition, such a higher power single drive unit maynot be capable of torque vectoring. Accordingly, the modular componentsof the present disclosure are able to satisfy both low-power andhigh-power builds (e.g., the same modular parts can be used in both).

Considering dual drive unit systems, in some embodiments, each motordrives one wheel. For example, a motor may correspond to, and have fullindependent torque control over, a wheel.

Modularity may also allow various components to be installed. In someembodiments, the present disclosure is directed to a configurationhaving a clutch mechanism installed between two output shafts, allowingthe drive units to be controllably coupled together. For example, in theevent that one wheel on a drive axis has limited traction (e.g., due tosnow, ice, or sand), a clutch may allow torque from both motors to beapplied to the wheel having traction (e.g., rather than just reducingtorque applied to the slipping wheel).

FIG. 9 shows illustrative panels of how clutch assembly 940 may beinstalled to couple drive units 920 and 930 together (e.g., in someembodiments, the same or similar drive units as FIG. 8 ), in accordancewith some embodiments of the present disclosure. Clutch mechanism 940may be coupled to each output shaft, output gear, or both, in dual driveunit 950. When engaged, clutch mechanism 940 locks the two output shaftstogether (e.g., allowing torque transfer between wheels). Whendisengaged, the output shafts can rotate independently of each other.For example, clutch mechanism 940 can be engaged when wheel slip isdetected in one of the wheels or when a vehicle is set to certaindriving modes. When clutch mechanism 940 is engaged and one wheel slips,the torque of both motors may be applied to the wheel that is notslipping which may be desired for, for example, maximum acceleration insplit-friction (“split p”) track conditions, or while driving in extremeoff-road conditions (e.g., rock-crawling). For example, when torquevectoring is desired, clutch mechanism 940 may be disengaged. In somecircumstances, the use of a clutch may also allow both wheels on a driveaxis to be driven by one motor, if the other motor experiences a failureor otherwise is inactive. Clutch assembly 940 may include any suitabletype of clutch, which may allow slip or not, and may operate dry or wet.For example, clutch assembly 940 may include a plate-type clutch (e.g.,with one or more pressure plates and friction disks), a cone-typeclutch, a centrifugal clutch, a torque limiting clutch (e.g., whichdisengages partially at high torque values), any other suitable type ofclutch, or any combination thereof. Clutch mechanism 940 may becontrolled in any suitable way such as, for example, a cable actuator, ahydraulic actuator, a pneumatic actuator, an electric actuator, or acombination thereof.

In some embodiments, drive unit 910 is similar to drive unit 810 of FIG.8 , and includes motor 911 configured to drive two wheels of a driveaxis via power transfer mechanism 912 and differential 917. Drive unit910 may be converted to drive unit 920 (e.g., no clutch), and thenincluded in a dual drive unit (e.g., dual drive unit 950 of FIG. 9 ).For example, the conversion from single drive unit to dual drive unitmay include removing differential 917 from drive unit 910 and installingclutch mechanism 940 between drive unit 920 and drive unit 930 to formdrive unit 950. Accordingly, clutch assembly 940 is configured to engagewith the output (e.g., either gear, shaft, flywheel, or other coupledoutput) of each of power transfer mechanisms 912 and 932. In someembodiments, clutch assembly 940 is configured to engage the two outputsto, for example, transfer torque between drive units 920 and 930. Dualdrive unit 950 may be used to, for example, drive both wheels with bothmotors, drive both wheels with one motor (e.g., if one motor is leftunpowered), drive one wheel primarily with both motors (e.g., if onewheel is slipping), lock-up the output shafts (e.g., similar to a spooltype differential), or otherwise provide additional control of dualdrive unit 950.

In some embodiments, installation of clutch assembly 940 may includeinstalling cover plates (e.g., cover plate 927 with suitablepass-throughs and mounting features) on a housing of each of powertransfer mechanisms 912 and 932. In some embodiments, clutch assembly940 includes a clutch housing which is aligned to housings of powertransfer mechanisms 912 and 932 (e.g., via pins, lips, steps, or otherlocating features). In some embodiments, the clutch housing may includeone or more bolt patterns (e.g., including through holes, threadedholes, studs, or other fastening features) for rigidly mounting theclutch assembly to power transfer mechanisms 912 and 932.

Dual drive unit 950 of FIG. 9 may be considered a combination of two “Z”type drive units, wherein each motor extends from the correspondingpower transfer mechanism on the opposite side from the correspondingdriven wheel (e.g., and corresponding half-shaft). A clutch mechanismmay also be used to couple “C” type drive units, such as dual drive unit500 shown illustratively in FIG. 5 .

FIG. 10 shows a block diagram of illustrative electric vehicle 1000having a control system for controlling one or more drive units, inaccordance with some embodiments of the present disclosure. Electricvehicle 1000 includes a battery pack, electric vehicle subsystems 1010,suspension, and wheels. Electrical vehicle subsystems 1010 includes, forexample, rear drive unit 1012, front drive unit 1014, control circuitry1016, auxiliary systems, and any other suitable corresponding equipment.

In some embodiments, control circuitry 1016 may include processingequipment, memory, power management components, any other suitablecomponents for controlling one or more drive unit (e.g., front driveunit 1014 and rear drive unit 1012), or any combination thereof. Forexample, control circuitry 1016 may control current flow (e.g., amountof current and current direction) to phases of an electric motor of oneor more drive units. In a further example, control circuitry 1016 maycontrol clutch operation (e.g., using an electromagnetically-actuatedclutch) in a dual drive unit. In a further example, control circuitry1016 may control differential operation (e.g., using anelectromagnetically-actuated differential) in a dual drive unit. In someembodiments, control circuitry 1016 may include one or more sensors, oneor more sensor interfaces (e.g., for sensors that are included as partof a drive unit), corresponding wiring, corresponding signalconditioning components, any other suitable components for sensing astate of a drive unit, or any combination thereof. For example, controlcircuitry may include a speed sensor (e.g., a rotary encoder), a currentsensor, a voltage sensor, a temperature sensor, any other suitablesensor, or any combination thereof. In some embodiments, controlcircuitry 1016 may be implemented by central controller, a plurality ofdistributed control systems, an embedded system, or any combinationthereof. For example, control circuitry 1016 may be at least partiallyimplemented by an electronic control unit (ECU). In a further example,the electric vehicle may include a power electronics system that iscontrolled by the ECU and is configured to manage current to one or moreelectric motors of one or more drive units. Rear drive unit 1012 may becoupled to wheels of the electric vehicle by a half shaft, aconstant-velocity joint, one or more suspension/steering components, anyother suitable coupling, or any suitable combination thereof. Frontdrive unit 1014 may be coupled to wheels of the electric vehicle by ahalf shaft, a constant-velocity joint, one or more suspension/steeringcomponents, any other suitable coupling, or any suitable combinationthereof. For example, a wheel may be mounted to a hub that is includes abearing for a half-shaft, wherein the hub is coupled tosuspension/steering components that are mounted to the vehicle frame(e.g., wherein the drive units are also mounted to the vehicle frame).

In some embodiments, a drive system may include a first drive unit, asecond drive unit, and a clutch assembly configured to transfer torquebetween the first and second drive units (e.g., as shown by dual driveunit 950 of FIG. 9 ). In some embodiments, a system, in addition toincluding a drive unit (e.g., single or dual), may include processingequipment configured to activate and deactivate the clutch assembly totransfer torque, manage motor operation, manage regeneration (e.g.,using the motor as a generator), perform any other control function, orany combination thereof. Activating and deactivating a clutch assemblymay refer to completely, or partially, increasing or decreasing theengagement of the first and second output shafts via the clutch assembly(e.g., using control circuitry). For example, activating a clutchassembly may include completely locking the clutch, allowing some slipof the clutch, or otherwise transferring an amount of torque between theoutput shafts. In some embodiments, the drive unit may include at leastone sensor (e.g., coupled to a sensor interface of control circuitry)configured to sense wheel slippage and the control circuitry may befurther configured to receive a signal from the at least one sensor,detect that wheel slippage is occurring, and activate the clutchassembly in response to detecting that wheel slippage is occurring. Forexample, a sensor may detect shaft speed (e.g., an output shaft speed,as measured by an encoder) or output torque (e.g., an output shafttorque, or a motor torque). In some embodiments, the drive system mayinclude an accelerator pedal configured to indicate a desired speed(e.g., by being depressed by a user), and the processing equipment mayreceive a signal from the accelerator pedal, determine a speed parameterbased on the signal, and activate the clutch assembly if the speedparameter is above a threshold. For example, if a user “floors” theaccelerator pedal (e.g., more than 50% demand), the control circuitrymay activate the clutch assembly to lock the output shafts together. Insome embodiments, the control circuitry may activate and deactivate theclutch assembly based on road conditions (e.g., icy roads, puddles, highwinds), a drive mode (e.g., an off-road mode, a sport mode, or atraction mode), any other suitable criterion, or any combinationthereof.

In some embodiments, one or more brackets, affixed at one or morelocations, may be used to rigidly connect the two motors of the dualdrive unit, two power transfer mechanism housings of the dual driveunit, or both, to ensure that all the components of the dual drive unitact as a single rigid body under normal operating conditions. In someembodiments, a boss, a tab, or other suitable feature may be included ona housing to aid in mounting.

It will be understood that the “V” shape is merely illustrative and anyother suitable orientations of the motors can be used. For example, insome embodiments, the two motors may be positioned on opposite sides ofthe output shafts such that motor axes and the common axis of the outputshafts are all aligned along a common line.

In some embodiments, one or more drive units may be included in avehicle. For example, Table 1 includes some illustrative configurationsin accordance with the present disclosure.

For any of the four illustrative examples included in Table 1 having asingle drive unit (“single”), a second drive unit may be installed inaccordance with the present disclosure to provide more power, provideimproved torque vectoring, or otherwise provide more control. Further, aclutch assembly may be included in any dual drive unit (“dual”),allowing transfer of torque between the output shafts on a drive axis.

TABLE 1 Illustrative drive unit arrangements in vehicles. High HighPerformance, Performance, All wheel twin torque with rear drive andvectoring twin torque small vehicle, Small vehicle, at both vectoringwith with the front and differential differential in and reardifferential in front front, and no drive axes in front and rear reardrive Front Rear Front Rear Front Rear Front Rear Dual Dual Single DualSingle Single Single None w/ Diff w/ Diff w/ Diff w/ Diff

It will be understood that the modularity of the present disclosure isnot limited to converting one drive unit configuration to another. Themodularity of the drive unit also enables one or more modular componentsto be assembled in one of multiple possible drive unit configurations.This has various advantages. For example, instead of designing, testing,and stocking different types of components for each drive unitconfiguration, a single modular component can be used for the differentdrive unit configurations. A modular power transfer mechanism can, forexample, be used to drive a single wheel or two wheels via adifferential. The modular power transfer mechanism can also be usedalone or together with a second modular power transfer mechanism. Whenused with a second modular power transfer mechanism, the mechanisms canbe used with or without a clutch assembly. Accordingly, the modularityprovides versatility and reduces costs.

FIG. 11 shows a perspective view of illustrative dual drive unit 1100having a single gear housing (e.g., gearbox 1112), in accordance withsome embodiments of the present disclosure. Dual drive unit 1100 maysimilar to, for example, dual drive unit 100 of FIG. 1 , except that asingle housing is included rather than two housings coupled together,although the drivetrain may still be referred to as having two halves.Dual drive unit 1100 includes motor 1110, motor 1120, and gearbox 1112(a housing, bearings, shafts, gearset, pulley set, and/or cog set) thatcouples the motors to respective gear trains (e.g., or pulleys, chainsor other suitable drive mechanisms) and respective output shafts (e.g.,such as output shaft 1114). In some embodiments, as illustrated, gearbox1112 may include one or more panels 1113 configured to provide access tothe internal region of gearbox 1112 (e.g., the gears, shafts, bearings,oil pump, or other components). For example, panel 1113 may include aflange, a bolt pattern, locating features (e.g., a pin or locatinghole), a seal (e.g., a gasket or O-ring), a sight glass, any othersuitable components, or any suitable combination thereof. In someembodiments, for example, gearbox 1112 may include two panels, one oneither side of the housing. In some embodiments, for example, thehousing of gearbox 1112 may be cast as a single piece. For example,gearbox 1112 may include two motor openings and two output openings. Insome embodiments, a gearbox housing need not include a panel (e.g.,access may be gained via motor openings or output openings). The use ofa single housing, rather than two coupled housings, may reduce or avoidthe need for alignment. Further, the use of a single housing may avoidthe need for interfacing structures (e.g., flanges, reinforcements,fasteners) that may add size or mass to the housing.

The foregoing is merely illustrative of the principles of thisdisclosure and various modifications may be made by those skilled in theart without departing from the scope of this disclosure. The abovedescribed embodiments are presented for purposes of illustration and notof limitation. The present disclosure also can take many forms otherthan those explicitly described herein. Accordingly, it is emphasizedthat this disclosure is not limited to the explicitly disclosed methods,systems, and apparatuses, but is intended to include variations to andmodifications thereof, which are within the spirit of the followingclaims.

What is claimed is:
 1. A drive system, comprising: a first powertransfer mechanism configured to couple a first motor shaft, a firstintermediate shaft, and a first output shaft configured to rotate abouta drive axis, wherein the first intermediate shaft is offset from afirst line extending from the first motor shaft to the first outputshaft; and a second power transfer mechanism configured to couple asecond motor shaft, a second intermediate shaft, and a second outputshaft configured to rotate about the drive axis, wherein the secondintermediate shaft is offset from a second line extending from thesecond motor shaft to the second output shaft, and wherein: the firstpower transfer mechanism comprises a first housing extending between thefirst motor shaft and the first output shaft; the first housingcomprises an indentation configured to accommodate the second motor andthe first intermediate shaft; the second power transfer mechanismcomprises a second housing extending between the second motor shaft andthe second output shaft; the second housing comprises an indentationconfigured to accommodate the first motor and the second intermediateshaft; and the indentations of the first housing and the second housingare configured to reduce an angle between the first and second lines. 2.The drive system of claim 1, wherein the first power transfer mechanismand the second power transfer mechanism each comprise a gear train. 3.The drive system of claim 2, wherein the gear train of the first powertransfer mechanism comprises: a first gear coupled to the first motorshaft; at least one second gear coupled to the first intermediate shaft;and a third gear coupled to the first output shaft, wherein the firstgear mechanically interfaces with the at least one second gear andwherein the at least one second gear mechanically interfaces with thethird gear.
 4. The drive system of claim 3, wherein: the at least onesecond gear comprises two gears coupled to the first intermediate shaft;the two gears comprise a first larger gear and a second smaller gear;the first larger gear mechanically interfaces with the first gear; thesecond smaller gear mechanically interfaces with the third gear; and thefirst power transfer mechanism and the second power transfer mechanismeach provide a gear reduction.
 5. The drive system of claim 3, whereinthe first intermediate shaft is offset from a line considered to extendfrom the first motor shaft to the first output shaft.
 6. The drivesystem of claim 1, wherein: the first power transfer mechanism comprisesa first end proximate to the first motor axis and a second end proximateto the first output shaft; the second end of the first power transfermechanism is located a first distance away from the first motor axis,which is greater than a distance from the first motor axis to an outerside surface of the first motor; the second power transfer mechanismcomprises a first end proximate to the second motor axis and a secondend proximate to the second output shaft; the second end of the secondpower transfer mechanism is located a second distance away from thesecond motor axis, which is greater than a distance from the secondmotor axis to an outer side surface of the second motor; and the secondend of the first power transfer mechanism is adjacent to the second endof the second power transfer mechanism.
 7. The drive system of claim 6,wherein the second end of the first power transfer mechanism ismechanically connected to the second end of the second power transfermechanism.
 8. The drive system of claim 1, wherein the first powertransfer mechanism and the second power transfer mechanism each comprisea chain drive or a belt drive.
 9. The drive system of claim 1, whereinthe first motor shaft and the second motor shaft at least partiallyoverlap when viewed in a direction perpendicular to the first motoraxis.
 10. The drive system of claim 1, wherein: the first motorcomprises a first motor housing; the second motor comprises a secondmotor housing; and the first motor housing and the second motor housingpartially overlap each other when viewed in a direction perpendicular tothe first motor axis.
 11. The drive system of claim 1, wherein the firstmotor shaft extends from the first motor in a first direction andwherein the first output shaft extends from the first power transfermechanism in the first direction.
 12. The drive system of claim 11,wherein the second motor shaft extends from the second motor in a seconddirection, wherein the second output shaft extends from the second powertransfer mechanism in the second direction, and wherein the firstdirection and second direction are opposite directions.
 13. The drivesystem of claim 1, wherein the angle between the first line and thesecond line is less than 90 degrees.
 14. The drive system of claim 1,further comprising: a first inverter configured to control the operationone of the first motor and the second motor, wherein the first inverteris aligned with first motor axis and mechanically coupled to the firstpower transfer mechanism; and a second inverter configured to controlthe operation the other of the first motor and the second motor, whereinthe second inverter is aligned with second motor axis and mechanicallycoupled to the second power transfer mechanism.
 15. The drive system ofclaim 1, further comprising a clutch assembly coupled to the firstoutput shaft and the second output shaft, wherein the clutch assembly,when engaged, is configured to lock the first output shaft and thesecond output shaft together.
 16. The drive system of claim 1, furthercomprising: a first half shaft, wherein a first end of the first halfshaft is coupled to the first output shaft; a first wheel, wherein asecond end of the first half shaft is coupled to the first wheel; asecond half shaft, wherein a first end of the second half shaft iscoupled to the second output shaft; and a second wheel, wherein a secondend of the second half shaft is coupled to the second wheel.
 17. A drivesystem, comprising: a first power transfer mechanism comprising a firsthousing and configured to couple rotation of a first motor shaft of afirst motor to rotation of a first output shaft about a drive axis usingan offset first intermediate gear, wherein the first motor shaft rotatesabout a first motor axis parallel to the drive axis; and a second powertransfer mechanism comprising a second housing and configured to couplerotation of a second motor shaft of a second motor to rotation of asecond output shaft about the drive axis using an offset secondintermediate gear, wherein the second motor shaft rotates about a secondmotor axis parallel to the drive axis and spaced apart from the firstmotor axis, and wherein: the first housing comprises a first indentationand a first protrusion configured to accommodate the offset firstintermediate gear and the second motor; and the second housing comprisesa second indentation and a second protrusion configured to accommodatethe offset second intermediate gear and the first motor.
 18. A drivesystem comprising: a first housing configured to couple rotation of afirst motor shaft of a first motor to rotation of a first output shaftabout a drive axis using an offset first intermediate gear; and a secondhousing configured to couple rotation of a second motor shaft of asecond motor to rotation of a second output shaft about the drive axisusing an offset second intermediate gear, wherein: the first housingcomprises a first indentation and a first protrusion to accommodate theoffset first intermediate gear and the second motor; and the secondhousing comprises a second indentation and a second protrusion toaccommodate the offset second intermediate and the first motor.